The present invention concerns a novel flash lamp and flash lamp assembly. The novel flash lamp has particular applications in circuitry for operation in parallel with a conventional incandescent light or lamp.
In emergency lights, such as emergency vehicle light bars, incandescent lamps having a dual contact bayonet base are often used. I have discovered a flash lamp assembly that can be easily substituted for this type of incandescent lamp. It is to be understood, however, that my invention is not limited to use in emergency vehicle light bars. My invention may take various forms in which a simple flash lamp assembly is provided having a two-contact circuit in contrast to the prior art three-contact circuits.
For example, a conventional flash tube has two end contacts which may be designated an anode and a cathode for convenience, although these designations may be arbitrary. The conventional flash lamp also has a trigger electrode, often in the form of a metal band. In conventional prior art flash circuits, all three electrodes must be connected to external circuitry, and thus the prior art flash tube assemblies cannot be merely inserted into an ordinary two-contact receptacle such as used with the conventional incandescent lamp.
In another aspect of my invention, I have developed circuitry in which my improved flash lamp assembly can be operated in parallel with a conventional incandescent lamp so that only a single power supply wire is required for connection. A conventional incandescent lamp and a conventional prior art flash lamp could be operated off the same power supply line only if the power source for the flash lamp was housed in the same package. For purpose of convenience in illustration, a schematic circuit in block diagram form showing this prior art construction is shown in FIG. 9 and has been designated with the legend "Prior Art".
This prior art arrangement suffers from the disadvantage of requiring the mounting of the power source in close proximity to the flash lamp which would be impractical where the flash lamp is installed in a remote location such as on the wingtips of an aircraft. Thus, not only would such construction require additional wiring, it would not be appropriate due to limitations of space and weight.
It is, therefore, an object of the present invention to provide a flash lamp that is insertable into an incandescent lamp receptacle.
Another object of the present invention is to provide a flash lamp in which the flash lamp assembly is formed in a unitary, integral construction.
A further object of the present invention is to provide a flash lamp assembly in which a flash tube, transformer, capacitor and base are coupled together to form a unitary, integral lamp, with all or a portion of the flash tube, the transformer and capacitor being encapsulated by a potting compound.
A further object of the present invention is to provide a flash lamp which is simple in construction and easy to manufacture.
Still another object of the present invention is to provide an electrical circuit including a novel flash lamp assembly and an conventional incandescent lamp connected in parallel and housed in a single package where the power supply for the same is adapted to be located at any desired remote area.
Other objects and advantages of the present invention will become apparent as the description proceeds.